Supercomputers Race to Predict Storms 184
pillageplunder writes "CNN has an interesting article on how different supercomputers from around the world are working to predict large storms tracks. The 3 days it takes now has been cut in half. Cool read."
the 3 days it takes? (Score:5, Informative)
I guess we should read articles before submitting them...
Re:Earth Simulator (Score:3, Informative)
Earth Simulator does - Atmosphere & Ocean Simulation, Solid Earth Simulation, Multiscale Simulation, and Advanced Precipitation Simulations. (And other cooperative projects).
Re:Earth Simulator (Score:4, Informative)
Re:Earth Simulator (Score:5, Informative)
A snip at $430 million...
Re:Using Fortran, eh? (Score:5, Informative)
i) because most numerical weather codes are already written in Fortran. This means that people with the right scientific knowledge tend to be Fortran programmers, and makes porting a whole lot easier.
ii) Fortran compilers are the ones where the most work has gone into optimising the hardcore mathematical routines. Thus, the compiled code has traditionally been faster. This may no longer be true.
Re:Using Fortran, eh? (Score:1, Informative)
Fortran supports a very large set of highly optimized intrinsics that have been perfected for numerical computations over many many years as well as vast libraries of parallel implementations.
Re:Fortran? (Score:2, Informative)
I saw in another post regarding my parent post that part of the reason is the tweaks for the fortran compilier being released.
I'm just trying to understand why they aren't moving to a more object oriented method of design for weather modeling. So they can drop in objects that don't require the entire code base to be recompiled.
Re:Fortran? Eyew. (Score:4, Informative)
Re:Pretty fast... (Score:3, Informative)
Re:Cool distributed computing idea. (Score:2, Informative)
Re:Land seem chaotic (Score:4, Informative)
So, with land, you leave the realm of an initial value problem with relatively well-understood boundary conditions that you have with a storm over the ocean to a realm that has much-less-well-understood boundary conditions. The problem becomes much harder to close, much less solve. And with a system like the hurricane which REQUIRES good knowledge of the boundary (after all, the hurricane is fueled by latent heat release by condensation of water vapor which comes from the ocean), not knowing the boundary as well as you can makes prediction much much harder.
Charley's swerve was forecast by a good number of models, but NHC played the worse case scenario card a little too long by persisting on a landfall near Tampa Bay.
Frances' stop was due to a very irregular pattern, much like a saddle point. If you are pushed any direction, you get very different behavior. You can see that on the following model ensemble plot... there's a small cluster of 48 hour predictions that are slower than the others.
http://euler.atmos.colostate.edu/~vigh/g
Ivan's bounce off Jamaica is a seriously cool research topic, since Jamaica is a mountainous island. That big elevation change could make it more "visible" to the core of the storm (unlike the plains of Florida). This will be a serious research topic for decades to come. Many of the models did not handle it well (which isn't too surprising since Jamaica is a relatively small island and the models that are used frequently are global or near-global models). And some previous storms (Gilbert, 1988) didn't even notice Jamaica as they passed over, so experience is a split decision.
So, hopefully that sheds a little insight on this issue. Land is a BIG problem for track forecasting, and we're just starting to work out the kinks.
-Jellisky
Re:the 3 days it takes? (Score:3, Informative)
When a tropical system is moving very slowly, it is prone to wobble a bit, so on a time scale as short as 1 hour, there will be a considerable spread in possible movements.
The forecasts for Frances were in fact EXTREMELY accurate. You can view a loop of NHC's forecast images here [noaa.gov]. If you do you will see that Frances made landfall almost exactly where the 3-day forecast said it would.